1. Field of the Invention
The present invention relates to an image forming apparatus configured to perform power saving processing, a method for controlling the image forming apparatus, and a program.
2. Description of the Related Art
In a recent image forming apparatus, a period of time elapsed since a user operated a power switch until the user can actually operate the apparatus has intended to be lengthened due to multifunctionalization or the like. One of factors is that software for operating a controller configured to control the image forming apparatus increases in scale as it is multifunctionalized.
On the other hand, there is a method for not actually powering off the whole image forming apparatus when a user performs a power-off operation but remaining a memory of the controller in a sort of a standby state where it remains powered on. In this method, a state during a normal operation of the controller is retained in the memory in the standby state. Thus, the image forming apparatus can be made operable in a short time using a content of the memory when the user performs a power-on operation next time.
However, the software on the controller has a large number of internal states. One example is a state of a screen to be displayed on an operation unit. In the above-described method, the content of the memory during the power-off operation is retained. When the image forming apparatus becomes operable, therefore, the state of the controller is similar to that during the power-off operation. Generally, the user who operates a power switch expects that the image forming apparatus is in a similar state to that when it is started from an original power-on state. Therefore, the above-described method is not preferable.
In addition, when the content of the memory of the controller continues to be retained, as described above, reset control is not applied to the software operating on the controller. A malfunction occurring when the software is not reset for a long time is generally known. One example is fragmentation of the memory, which causes an operating speed to be reduced and causes an abnormality to occur in an operation. Ideally, the software is also preferably reset.
Therefore, a method can be considered which performs reboot once when the user performs the power-off operation, and then retains the content of the memory to bring the controller into the standby state. Such a configuration can ensure that an internal state of the controller retained in the memory is similar to that when the image forming apparatus is started using a normal method. Further, the software can be reset by performing the reboot.
On the other hand, when the image forming apparatus actually performs operations such as copying and printing after the user performs the power-on operation, respective engines of a printer unit and a scanner unit are required to complete their adjustment operations. Therefore, the adjustment operations of the engines are generally started in synchronization with startup of the controller and return from a power saving state to shorten a waiting time elapsed since the power-on operation was performed. When the above-described method including the reboot is introduced into the image forming apparatus, the adjustment operations of the engines are performed during the reboot, so that useless power is consumed and an operating sound may increase.
On the other hand, as a conventional technique, there is a technique for controlling determination whether start of an adjustment operation of an engine is synchronized with startup of a controller and return from a power saving state by a signal line connected between the controller and the engine (Japanese Patent Application Laid-Open No. 2008-122752). In this discussion, if the controller notifies an image forming unit (engine) that the adjustment operation is not synchronized via the signal line, the adjustment operation is performed before an operation such as printing is performed later.
However, in a configuration discussed in the conventional technique, the notification via the signal line as to whether the adjustment operation of the engine is synchronized is controlled only when the image forming apparatus returns from the power saving state. More specifically, in the conventional technique, when the power saving state of the image forming apparatus is released, control for changing the notification via the signal line is performed under condition of a factor of release. In the conventional image forming apparatus, the notification of the determination whether the adjustment operation is synchronized at the time of startup of the controller is neither controlled nor changed depending on the condition or the like.
If the user performs a power-off operation for the image forming apparatus, therefore, it is difficult to perform control so as not to perform the adjustment operation of the engine when a method for retaining a content of a memory to bring the controller into a standby state after reboot is performed once is used.